1. Technical Field
The present invention relates generally to socks, and, more specifically, to a two-ply sock whose dimension and fit is adjustable by the wearer.
2. Background
Blisters are commonly caused by a persistent physical trauma, such as the rubbing of the heel against the inner surface of a shoe. Though blisters can affect anyone, certain individuals are predisposed to this problem. Those with narrow feet, especially in the heel, along with those who have slightly different sized feet, are prone to blisters due to the ill-fitting nature of off-the-rack shoes. For these individuals, blistering becomes more pronounced during athletic activity, such as hiking, jogging, golfing and any other activity where prolonged walking or running is required. As the heel is not securely held against the back of the shoe, but instead slides back and forth against the inner wall of the shoe, a blister develops. The toes may also develop blisters or bruises from the action of the foot sliding forward in the shoe, crunching the toes against the tip of the shoe.
The foot of a diabetic, or one with an impaired circulatory system, is even more susceptible to trauma, particularly around the heel and bony prominences of the foot. Foot ulcers are not uncommon and may lead to infection and gangrene. Due to diabetic neuropathy, the individual may not perceive the trauma, thus complicating the condition.
Further complications are caused by the dank environment to which the foot is exposed during long bouts of activity. Sweat encourages fungal and bacterial. invasions, as does moisture seeping in from outside sources.
Some have attempted to design shoes or socks having adjustable features to increase comfort, such as those disclosed in U.S. Pat. Nos. 2,582,648; 3,431,658; 3,760,056; 4,724,627; 4,995,173; 5,257,470; 5,317,821; and 5,329,640.
Hourigan (U.S. Pat. No. 5,329,640) discloses an adjustably cushioned sock including flexible tubing positioned internally of the sock to receive and retain air therein. The tubing is formed so as to constitute two separate independent circuits--one extending over the top of the foot and serving to cushion the instep and ankle and the other extending to provide cushioning for the underside of the foot. A pump is provided to supply air to each circuit, and a release valve permits the air contained therein to be exhausted. The inventor specifies that the socks can be used to compensate for slight misfits in shoes by controlling the amount and location of the inflation.
However, Hourigan's focus on cushioning the instep, ankle, and underside of the foot results in an inordinate amount of structure within the sock, and, while allowing for adjustment, the sock appears to be alterable almost exclusively in the vertical plane, i.e. cushion is provided above and below the foot. Hourigan is not concerned with protecting the contours of the heel and toes against physical trauma caused by heel slippage and the cramming of the toes against the tip of the shoe. Nor does he deal with problems caused by excessive moisture about the foot.
It is thus an object of the present invention to provide an inflatable sock having minimal internal structure whose dimension and fit is adjustable by the wearer so that it may securely, firmly, yet softly hold the heel in place and so that the toes are not pummelled against the tip of a shoe or boot.
It is a further object to provide persons having slightly different sized feet with a comfortable sock-like garment that adapts to the size of the misfit shoe.
It is another object to provide diabetic persons with a sock that protects the foot from trauma caused by ill-fitting shoes, pebbles, and the like, while at the same time preventing a moisture build up that might lead to infection or other complication.